Apparatus and process for removing flexible film seals from tubular specimen containers

ABSTRACT

It is described an apparatus for removing a flexible film seal ( 12 ) from a tubular specimen container ( 3 ), comprising a vertical mounting shaft ( 5 ) upon which is mounted a holding member ( 6 ) for a head assembly ( 9 ) having a cavity ( 13 ) and pinch means ( 14, 15 ). There is provided driving means for causing coupling motion of said head assembly ( 9 ) and said specimen container ( 3 ) towards each other to receive the seal ( 12 ) into said cavity ( 13 ), then operating said pinch means for pinching the flexible film seal ( 12 ), and finally causing removing motions of said head assembly ( 9 ) and said specimen container ( 3 ) away from each other to remove the flexible film seal ( 12 ) from the head of the specimen container ( 3 ).

The present invention concerns an apparatus and a process for removingflexible film seals from tubular specimen containers.

As used herein, the term “container” means an article that contains asolid or liquid and has a tubular opening for access of the contents,e.g., a test tube or vial.

Flexible film seals means “foil or film closure” that is any thinmembranous material that covers, seals, and overhangs the annularopening at the top of a container so defined and is bonded to it in sucha way that it can be torn free from the opening with a mechanicalpulling force applied to the overhanging portion. The word “seal” isused to refer synonymously to a particular foil or film closure ofinterest.

In modern medical analysis systems, after having removed the cap fromthe specimen containers for a medical analysis, the openings of saidcontainers are closed by flexible film seals.

If, for any reason, a new test needs to be performed an operator mustmanually remove the seal, and return the container to the analyser.

This means waste of time and explosure of the operator to biologicalhazard.

Object of the present invention is to provide an automatic apparatus anda process for removing flexible film seals from tubular containers.

According to the invention said object is achieved by an apparatus forremoving a flexible film seal from a tubular specimen container,characterized in that it comprises a vertical mounting shaft upon whichis mounted a holding member for a head assembly having a cavity andpinch means, there being provided driving means for causing couplingmotion of said head assembly and said specimen container towards eachother to receive the seal into said cavity, then operating said pinchmeans for pinching the flexible film seal, and finally causing removingmotions of said head assembly and said specimen container away from eachother to remove the flexible film seal from the head of the specimencontainer.

According to the invention said object is further achieved by a processfor removing a flexible film seal from a tubular specimen container byan apparatus according to claims 1-20, characterized in that itcomprises the following steps:

-   -   immobilization of the specimen container;    -   coupling motion of said head assembly and said specimen        container towards each other to receive the seal into said        cavity;    -   pinching of a portion of the free flexible film seal;    -   removing motion of said head assembly and said specimen        container away from each other to remove the flexible film seal        from the top of the specimen container.

The characteristics and advantages of the present invention will appearevident from the following detailed description of an embodiment thereofillustrated as non-limiting example in the enclosed drawings, in which:

FIG. 1 is a perspective view of the apparatus according to the presentinvention with an enlarged part;

FIG. 2 is a top view of the apparatus of FIG. 1;

FIG. 3 is a lateral sectional view according to line III-III of FIG. 2;

FIG. 4 is the same lateral sectional view of FIG. 3 in a subsequentworking position;

FIG. 5 is the same lateral sectional view of FIG. 4 in a subsequentworking position;

FIG. 6 is the same lateral sectional view of FIG. 5, with an enlargedpart, in a subsequent working position;

FIG. 7 is the same lateral sectional view of FIG. 6 in a subsequentworking position;

FIG. 8 is the same lateral sectional view of FIG. 7, with an enlargedpart, in a subsequent working position;

FIG. 9 is the same lateral sectional view of FIG. 6 in a subsequentworking position;

FIG. 10 is a top view with the head assembly rotated of substantially90°;

FIG. 11 is a lateral sectional view according to line XI-XI of FIG. 10;

FIG. 12 is the same lateral sectional view of FIG. 11 in a subsequentworking position;

FIG. 13 is the same lateral sectional view of FIG. 12 in a subsequentworking position;

FIG. 14 is a sectional view according to line XIV-XIV of FIG. 3.

Referring now to FIGS. 1 through 14, an apparatus for removing aflexible film seal 12 from a tubolar specimen specimen container 3, ismounted to a frame 1 of a conveyor system or parent system, in which theapparatus is incorporated, that processes the specimen container 3. Eachspecimen container 3 is presented by the parent (conveyor) system to aspecific point in space in the system at which point the apparatus willremove the flexible film seal 12.

The apparatus is mounted next to a track (not shown) of the parentsystem on a platform 2 or similar support.

An articulated pair of gripping arms 4 is incorporated into theapparatus to engage and hold the specimen container 3 during the sealremoval operations to be described in FIGS. 3 through 7.

Each one of said gripping arms 4 (FIG. 12) comprises an external portion61 and an internal portion 60 connected by a transversal central pin 62and a couple of fingers 63, whose surface may be covered with rubber toincrease the gripping capabilities of said fingers at the moment theygrab the container, which pin allows a little rotation (few degrees) ofthe internal part 60, supporting the specimen container 3, with respectto the external part 61.

The gripping arms 4 are actuated by mechanical means 11 which do notneed be part of the specimen removing apparatus.

Referring to FIG. 1, the embodiment of the apparatus is comprised of avertical mounting shaft 5 upon which is mounted a bracket 6 for holdinga seal removing head assembly 9. The shaft 5 is mounted in a bearing andis actuated by mechanical drive means to provide vertical travel to allcomponents attached to it by means of the bracket 6.

A pneumatic cylinder motor is used in the current embodiment, but othermechanical drive means, such as a motorized rack and pinion gear mayalso be embodied.

The head assembly 9 is mounted in such a way that it pivots through asmall angle in the mounting bracket 6 along a horizontal axis throughthe head. The degree of rotation about this axis and the orientation ofthe axis are important relative to the position of the opening in thespecimen container 3 during the removal operation and are describedlater.

The pivoting impetus is provided to the head assembly 9 in thisembodiment by a pneumatic cylinder 7 attached to the mounting bracket 6and connected to a rotating linkage 8 that is, in turn, attached to thehead assembly 9. Other means for actuating the pivot, such as anelectric motor and gear assembly, may also be embodied.

The entire seal removing mechanism, consisting of shaft 5, mountingbracket 6, pneumatic cylinder 7, rotating linkage 8, and head assembly9, is rotated around the shaft 5 in order to position the head assembly9 directly above one of two relevant stations for its active use.

The first station (FIGS. 1-9) is the position at which the head assembly9 is directly above the specimen container 3 as it is presented by thetrack or conveyor of the parent system.

The second relevant position (FIGS. 10-13) is that of a waste chute 21into which the waste seal 12 will be ejected after being removed fromthe specimen container 3. Said waste chute 21 is provided with a passagedetecting sensor (not shown) for the removed flexible film seal 12.

In the embodiment shown, these two positions are 90° apart around thecircular travel of the head assembly 9 as afforded by the rotation ofthe shaft 5; however, the angular separation of the two is not relevantto the invention and can take on any value that is mechanicallyfeasible. It is further possible to produce other embodiments of motionfor the head assembly 9 that do not involve circular motion, e.g. arectilinear positioning mechanism and suitable drives.

Driving force for the rotational positioning embodiment shown isprovided by a pneumatic cylinder (not shown) applied to the shaft 5 butthere may also be any suitable drive means such as an electric motor andplenary gear system or the like.

The head assembly 9 comprises a conical cavity 13, an upper pinch plate14, a lower pinch plate 15 and a pusher arm 17, driven by a piston of apneumatic cylinder 16, to force a portion 20 of the seal 12 between saidpinch plates 14-15.

Said head assembly 9 further comprises a detecting sensor 22 whichcontrols the seal grab by the upper and lower pinch plates 14-15.

The start of the seal removing operation by the apparatus of theinvention is marked by the conditions illustrated in FIG. 3. The parentsystem has previously positioned the specimen container 3 of interest tothe designated station for closure removal. The specimen container 3bears the seal 12 that is to be removed by the apparatus. The specimencontainer 3 has further been immobilized by the gripping arms 4 closedupon it by a motor and gearing mechanism 11 attached to the mountingplatform 2.

Initially the shaft 5 and attached elements are extended upwardly by thevertical drive means to a vertical height sufficient to allow mechanicalclearance for positioning the specimen container 3 at the designatedseal removal station by the parent system. The shaft 5 is furtherrotated by the rotational drive means to center the head assembly 9above the designated seal removal station. Centering of the headassembly 9 is defined relative to a cavity 13 in the underside of theassembly that is substantially circular in cross section withsubstantially conical walls and depth sufficient to surround the top ofthe specimen container 3 and seal 12 with particular mechanismscontained in the head assembly 9 and discussed below.

For the purpose of the following discussions, the “back” or “backward”direction relative to the head assembly 9 is toward the shaft 5. The“front” or “forward” direction is away from the shaft 5.

Initially, the pneumatic cylinder 7 is actuated such that the linkage 8is drawn toward the cylinder 7, causing the head assembly 9 to pivotbackward (counterclockwise rotation, FIG. 3) with the upper portion ofthe head assembly 9 closer to the shaft 5 than the lower portion. Thelatter contains the pivot axis 80 in contact with the mounting bracket6. Specifically, said axis 80 belongs or is at least parallel to theplane of the upper pinch plate 14. In this position, the major axis ofthe substantially cylindrical head assembly 9 forms an angle ofapproximately 5° with the vertical.

By displacing the head 9 in the backward tilt position, the cavity 13for receiving the tubular top portion or head 50 of the specimencontainer 3, is slightly biased toward the back of the containeropening, that is, the side of the opening closest to the shaft 5.

In the next operation (FIG. 4) in the seal removing sequence, headassembly 9 is lowered onto the specimen container 3, and therefore alsoonto the seal 12 by means of the vertical drive mechanism associatedwith the shaft 5.

By virtue of its conical nature, the cavity 13 in the bottom of the headassembly 9 serves to guide the head onto the tubular top 50 of thespecimen container 3.

Next the pneumatic cylinder 7 is moved to the outward position(clockwise rotation around the pivot axis 80) so as to move the linkage8 forward, tilting the head assembly 9 forward, to the upper positionatop the specimen container 3 as illustrated in FIG. 5. In thisposition, the major axis of the substantially cylindrical head assembly9 is aligned with the vertical.

The uppermost surface of the cavity 13 in the head assembly 9 is theupper pinch plate 14, which rests upon the seal 12 atop the specimencontainer 3.

Next the pneumatic cylinder 7 is moved again to the outward position(clockwise rotation around the pivot axis 80, FIG. 6), so as to form anangle of approximately 5° with the vertical. This rotation causes thetilting of the specimen container 3 due to the rotation of the internalpart 60 (see enlarged part).

In FIG. 6 is shown a small gap between the upper pinch plate 14 and thelower pinch plate 15, on the order of a few millimeters. Thus, a portion20 of the overhanging seal 12 is resident between the upper pinch plate14 and the lower pinch plate 15.

A pusher arm 17 is attached to the piston of the pneumatic cylinder 16such that it can be driven forward and backward within the cavity 13inside the head assembly 9. The cylinder 16 and the pusher arm 17 aremounted to the upper pinch plate 14. Other embodiments of the actuatedpusher arm might include an electric solenoid and shaft.

In the embodiment shown, the pusher arm 17 has been actuated by thecylinder 16 to push it forward inside the cavity 13 until it impinges onthe back side of the specimen container 3 and seal 12. This also forcesthe top of the specimen container 3 (slightly tilting said specimencontainer 3 allowed by the pins 63 of the gripping arms 4) and seal 12forward in the cavity 13.

Since there is a gap between the upper pinch plate 14 and the lowerpinch plate 15, and the tubular top and seal 12 are flush against thebottom of the upper pinch plate 14, this insures that a portion 20 ofthe overhanging seal 12 is between the two pinch plates 14, 15 and thatthe specimen container 3 is applied forcibly to the lower pinch plate atthe point tangent to the circle formed by the outside of the tubular topof the specimen container 3.

Referring to FIG. 7, the upper pinch plate 14 within the head assembly 9is attached to a pinch drive shaft 19, which forms the piston of apneumatic cylinder motor 18 within the head assembly 9. This is used inthe current embodiment to force the upper pinch plate 14 against thehead of the container (3) so providing the upward movement of the lowerpinch plate 15 with the head assembly 9 (and the shaft 5).

Therefore a pinching portion 20 occurs between the pinch plates 14,15.

During the removing motions said axis 80 belongs or is almost parallelto the upper pinch plane 14, and almost tangent to the closest portionof the circumference of the tubular specimen container 3.

The rotation of the head assembly 9, during the removing motions, towardthe vertical shaft 5, allows the opposite part to move up thereforepulling up the flexible film seal 12. The following raising of the headassembly 9 drags the flexible film seal 12.

The motion of the pinch drive shaft 19 might also be achieved with otherembodiments such as an electronic solenoid and shaft assembly.

Next the pusher arm 17 is retracted by reversing the actuating force onthe pneumatic cylinder 16 to move out of the cavity 13, as the pusherarm 17 is no longer needed once there is a grasp on the container bymeans of the pinched seal 12.

An important and distinguishing aspect of the apparatus and method ofthe invention is the motion that follows. The linkage 8 is drawnbackward by the pneumatic cylinder 7 which drives it, causing the headassembly 9 to rotate backwards (counterclockwise rotation, FIG. 8)through an angle of approximately 10° (approximately 5° with thevertical), taking the pinched portion of the seal 12 with it from thepinch point 20 (FIG. 7). As mentioned earlier, the axis for thisrotation of the head assembly 9 is positioned strategically relative tothe opening in the specimen container 3. To with, the axis of rotationis in the same plane as the circle prescribed by the opening in thespecimen container 3 (so almost belonging or parallel to the plane ofthe upper pinch plane), and is tangent to it at a point diametricallyopposed to the pinch point 20 at the front of the circle. The net effectof this orientation is that the seal 12 is pulled up and back relativeto the opening to which it is attached along a circular arc, the radiusof which is approximately the width of the opening. The result of thisparticular lifting geometry is to avoid tensile forces on the seal 12itself, enabling the entire lifting force on the seal 12 to be appliedtoward rupturing the bond between the seal 12 and the specimen container3. This, in turn, leads to a clean parting of the seal from the openingof the container such that the opening is free of detritus from the seal12 and amenable to reapplication of a subsequent seal.

The action performed by the backward rotation (counterclockwiserotation) of the head assembly 9 performs the initial rupture of thebond between seal 12 and specimen container 3 at the pinch point 20 andpropagates the rupture through a portion of the circle prescribed by theopening and the bond.

The portion varies according to the ductility of the foil or filmconstituting the seal 12, as a more ductile material will tend tostretch and absorb some of the parting force, thus parting less of theportion of the circular bond. A more refractory material will transmitmore of the parting force through the seal, causing a greater portion ofthe circular bond to be ruptured.

The remaining portion of the bond is then ruptured in a second motion byraising the entire head assembly 9 by means of the vertical drive on theshaft 5. As the head assembly 9 rises along with the shaft 5 andmounting bracket 6 to which it is attached, it takes the seal 12 alongwith it, pulling it from the specimen container 3 and rupturing theremaining bond with the circular opening (FIG. 9). However, in this casethe parting motion does not follow the circular arc prescribed by thediameter of the seal.

Instead the seal is pulled in a direction perpendicular to the plane ofthe circle which prescribes the opening of the specimen container 3,causing the seal to form a plane between the pinch point 20 and thepoints on the circle at which the bond is not yet ruptured. Since theparting action applied by the initial rotation of the head assembly 9has already ruptured a portion of the circular bond prior to thismotion, the angle at which the straight line formed by the plane of theseal intersects the plane of the opening is steep, causing the majorityof the vertical force vector to apply to the remaining bond points.

Without the initial rotational parting motion which began the bondrupture, this would not have been the case. That is, if the headassembly 9 has merely been raised vertically subsequent to forming thepinching grasp on the seal 12 at the pinch point, as in FIG. 5, theangle which the plane of the seal 12 forms with the plane of the openingat that point is zero, meaning that the entire vertical force would beentirely applied to the overhanging seal material itself and not to thebonding plane, resulting in high ductile deformation of the sealmaterial prior to beginning the rupture of the bond. Under suchconditions the bond does not part cleanly and the circular opening ofthe specimen container 3 is not amenable to the reapplication of asubsequent seal due to detritus left by the torn seal 12 and poorlyruptured bond.

Following removal of the seal 12 from the specimen container 3, thewaste seal 12 remains in the grasp of the pinch plates 14, 15 at thepinch point 20 in the head assembly as depicted in FIG. 9, where thedetecting sensor 22 controls the effective presence of said waste seal.

In the next step performed by the apparatus, the rotational driveassociated with the shaft 5 is engaged to rotate the entire assemblysuch that the head assembly 9 is positioned directly over the wastechute 21 (FIGS. 8-11). The vertical drive associated with the shaft 5 isthen engaged to lower the head assembly 9 until its lower surface restson the upper surface of the waste chute opening, as depicted in FIG. 10.The opening of the waste chute forms a substantially circular platformonto which the weight of the head assembly 9 rests in the downwardposition. The pneumatic cylinder 18 is pressurized such that the pinchdrive shaft 19 is driven up, thereby raising the upper pinch plate 14 towhich it is attached. This reforms the gap between the upper pinch plate14 and the lower pinch plate 15, allowing the grasp on the waste seal 12to be released.

Since the pinched seal material often adheres to the pinch plates, it isforcibly ejected from the cavity 13 in the head assembly by pressurizedair means 23 contained within the head assembly through a hole in theupper pinch plate 14 which is so positioned as to be centered on theapproximately circular area occupied by the waste seal once removed.

Contemporaneously to the action of the pressurized air, the sensor 22 ismonitoring the release of the seal. Such sensor, in this embodiment, isrealized with an optical fiber that conveys the optical signal, bycapturing the optical beam reflected by the seal when said seal ispresent. Other optical devices can be used for such monitoring action.

The waste chute 21 is equipped with a detecting passage sensor (90)(FIG. 13) that monitors the waste chute and can detect the passage ofthe waste seal through the chute. In the current embodiment, the sensoris an optical interrupter, but other embodiments capable of detectingthe passage of the waste seal 21 are possible. The signal from thesensor is provided to the parent system such that it can determine thesuccess of the seal removal operation performed by the apparatus byassumption derived from the passage of the waste seal through the wastechute.

Finally, the head assembly 9 is driven back to the upper position byengaging the vertical drive associated with the shaft 5, and thenreturned to the starting position over the seal removal station byengaging the rotational drive associated with the shaft 5, thuscompleting the seal removal operation and making ready for the nextcycle of same.

It may happen that the head assembly 9 is not successful to take andremove the seal.

In this case the removal operation may be repeated upon rotation of thespecimen container 3 with respect to the original position.

1. Apparatus for removing a flexible film seal (12) from a tubularspecimen container (3), characterized in that it comprises a verticalmounting shaft (5) upon which is mounted a holding member (6) for a headassembly (9) having a cavity (13) and pinch means (14, 15), there beingprovided driving means for causing coupling motion of said head assembly(9) and said specimen container (3) towards each other to receive theseal (12) into said cavity (13), then operating said pinch means forpinching the flexible film seal (12), and finally causing removingmotions of said head assembly (9) and said specimen container (3) awayfrom each other to remove the flexible film seal (12) from the head ofthe specimen container (3).
 2. Apparatus according to claim 1,characterized in that said removing motions comprise firstly a rotationof the head assembly (9) such that its upper part moves toward the shaft(5) to pull tip the flexible film seal (12), and secondly a raising ofthe head assembly (9) to drag the flexible film seal (12).
 3. Apparatusaccording to claim 2, characterized in that said rotation of the headassembly (9) is carried out around an axis that belongs to the plane ofan upper pinch plate (14) and almost tangent to the closest portion ofthe circumference of the tubular specimen container (3).
 4. Apparatusaccording to claim 2, characterized in that said rotation of the headassembly (9) is carried out around an axis parallel to the plane of theupper pinch plate (14) and almost tangent to the closest portion of thecircumference of the tubular specimen container (3).
 5. Apparatusaccording to claim 1, characterized in that said coupling motioncomprises firstly a rotation of the head assembly (9) such that itsupper part moves toward the shaft (5), secondly a lowering motion ontothe specimen container (3) to guide the cavity (13) onto the head of thecontainer (3), and finally a rotation of the head assembly (9) to anupper position.
 6. Apparatus according to claim 1, characterized in thatsaid cavity is conical for guiding the head assembly (9) onto the headof the container (3).
 7. Apparatus according to claim 1, characterizedin that it comprises an tipper pinch plate (14) and a lower pinch plate(15) relatively movable by driving means (18-19) for pinching a portion(20) of flexible film seal (12).
 8. Apparatus according to claim 1,characterized in that the vertical movement of the head assembly (9)obtained by the vertical shaft (5) can afford the desealing operation ofspecimen containers (3) of different height.
 9. Apparatus according toclaim 1, characterized in that it comprises pushing means (17), movableby driving means (16), for forcing the pinching portion (20) of theflexible film seal (12) between the pinch means (14, 15).
 10. Apparatusaccording to claim 1, characterized in that it comprises containergripping means (4), movable by driving means, providing immobilizationof the specimen container (3).
 11. Apparatus according to claim 10,characterized in that said container gripping means (4) comprises anexternal part (61) connected to an internal part (60) by at least adeformable element (63) allowing a slight rotation of said internal part(60) with respect to said external part (61).
 12. Apparatus according toclaim 1, characterized in that said head assembly (9) is mounted in sucha way that it pivots in the holding member (6) along a horizontal axis.13. Apparatus according to claim 1, characterized in that said headassembly (9) comprises a seal detecting sensor (22).
 14. Apparatusaccording to claim 1, characterized in that said holding membercomprises a bracket (6).
 15. Apparatus according to claim 1,characterized in that it comprises driving leans (7) attached to thebracket (6) and connected to a rotating linkage (8) that is, in tun,attached to the head assembly (9).
 16. Apparatus according to claim 1,characterized in that it comprises a waste chute (21) for the removedseal (12).
 17. Apparatus according to claim 12, characterized in thatsaid waste chute (21) comprises a passage detecting sensor (90). 18.Apparatus according to claim 1, characterized in that it comprisespressurized air means (23) for forcibly ejecting the waste seal (12)from the cavity (13).
 19. Apparatus according to claim 1, characterizedin that said container (3) is supported by a handling track of aconveyor system.
 20. Apparatus according to claim 1, characterized inthat said driving means comprise mechanical means.
 21. Apparatusaccording to claim 1, characterized in that said driving means compriseelectronic means.
 22. Apparatus according to claim 1, characterized inthat said driving means comprise pneumatic means.
 23. Apparatusaccording to claim 1, characterized in that said driving means comprisemagnetic means.
 24. Apparatus according to claim 1, characterized inthat it comprises control means for interacting with a conveyor system.25. Process for removing a flexible film seal (12) from a tubularspecimen container (3) by an apparatus according to claim 1,characterized in that it comprises the following steps: immobilizationof the specimen container (3); coupling motion of said head assembly (9)and said specimen container (3) towards each other to receive the seal(12) into said cavity (13); pinching of a portion (20) of the flexiblefilm seal (12); multiple and different removing motions of said headassembly (9) and said specimen container (3) away from each other toremove the flexible film seal (12) from the head of the specimencontainer (3).
 26. Process according to claim 25, characterized in thatit comprises the wasting of the removed flexible film seal (12). 27.Process according to claim 25, characterized in that said wasting isprovided by air pressured means (22).
 28. Process according to claim 25,characterized in that it comprises the forcing of the flexible film seal(12) between the pinch means (14, 15).
 29. Process according to claim25, characterized in that said coupling is provided firstly by arotation of the head assembly (9) such that its upper part moves towardthe shaft (5), secondly by a lowered motion onto the container (3) toguide the cavity (13) onto the head of the container (3), and finally bya rotation of the head assembly (9) to an upper position.
 30. Processaccording to claim 25, characterized in that said removing is providedfirstly by a rotation of the head assembly (9) such that its upper partmoves toward the shaft (5) to pull up the flexible film seal (12), andsecondly by rising the head assembly (9) to drag the flexible film seal(12).
 31. Process according to claim 25, characterized in that in caseof unsuccessful removal operation, steps of claim 25 are repeated uponrotation of the specimen container (3) with respect to the originalposition.